In semiconductor technologies, a semiconductor wafer is processed through various fabrication steps to form integrated circuits. Typically, several circuits are formed onto the same semiconductor wafer. The wafer is then diced to cut out the circuits formed thereon.
To protect the circuitry from damage, a seal ring is formed around the circuitry. This seal ring is formed during fabrication of the many layers that comprise the circuit, including both the front-end-of-line (FEOL) processing and back-end-of-line processing (BEOL). The FEOL includes the actual components such as transistors, capacitors, diodes, and resistors that are formed onto the semiconductor substrate. The BEOL includes the metal layer interconnects and vias that provide routing to the components of the FEOL.
During BEOL processing, a solid metal layer is formed around the circuit to form part of the seal ring for that level. Similarly, during the FEOL processing, the portion of the seal ring on those levels is formed. In some cases, an isolation zone is formed between the seal ring and the circuitry. If the circuitry includes gate structures formed over fin structures, then the isolation zone will have dummy features that include dummy gates and dummy fin structures.
It is desirable to have a seal ring design and isolation zone design that can provide a high quality seal and not have adverse effects on the circuitry within the seal ring.